Printing machine



A ril 17, 1934. J. F. SPRINGSTEAD PRINTING MACHINE INVENTOR: 31%

Patented Apr. 17, 1934 V UNITED STATES FATE FFm

PRINTING MACHINE pany, receiver Application October 23, 1931, Serial No.570,542

6 Claims.

My invention relates to printing machines, and more particularly to thatclass of printing machines which are adapted to print according to therotary photcgravure method.

Printing machines of the kind referred to usually comprise a formcylinder having a copper surface on which the matter to be printed isetched, the cylinder being mounted to rotate in an ink fountainunderneath the same, and having adjustably located near the upper partof the cylinder a doctor blade which removes surplus ink. The paper isled from a web roll and passes over the form cylinder, but according tothe present practice touches the same only momentarily and at a verysmall portion of its periphery. It has been found that such a momentaryimpression, while the same may be efficient with regard to ordinaryprinting, does not produce satisfactory results in practicing the rotaryphotogravure art.

It is therefore one of the principal objects of my invention to providemeans whereby the paper, on being led from the web roll, is held incontact with the rotating form cylinder for an appreciable time, that isto say, the portion of the periphery of the form cylinder with which thepaper comes into contact is quite substantially increased.

Further objects and advantages of the invention will be in part setforth in the following specification and in part will be obvioustherefrom without being specifically pointed out, the same beingrealized and attained by means of the instrumentalities and structuralcharacteristics and relative arrangements and combinations which will behereinafter more fully described or which will be pointed out in theclaims hereof.

With the above and other objects of the invention in view, the inventionconsists in the novel construction, arrangement and combination ofvarious devices, elements and parts, as set forth in the claims hereof,one embodiment of the same being illustrated in the accompanying drawingand described in this specification.

In the accompanying drawing,

Figure l is a side elevation of a portion of a printing machineembodying my invention, and

Fig. 2 is a detail view taken at right angles to Fig. 1, as indicated atthe left-hand side of Fig. l by the arrow marked 2.

In carrying my invention into efi'ect, in the embodiment thereof whichhas been selected for illustration in the accompanying drawing and fordescription in this specification, I provide a shown in the drawing)over the roll G, under the roll H and over to the form cylinder A,passing between the same and the impression cylinder B. The paper passesover the form cylinder for a substantial distance, and under theauxiliary impression roller K, then upward and over the roller L and upto the heated drum D, passing nearly entirely around the same and downto the guide roll M, and away from this part of the machine, asindicated at N. An ink fountain J is located below the form cylinder A,the lower part of which dips into the fountain and receives ink, thesurplus of which is removed, as the formcylinder rotates in acounterclockwise direction, by the doctor blade C.

The auxiliary impression roller K is shown in the drawing as adjustablypressed against the form cylinder A, and this is the preferableconstruction, but this auxiliary roller K need not be adjusted so as toactually press the paper against the form cylinder, but may be, ifdesired, spaced away from the form cylinder, though still maintaining asubstantial arc of contact of the web with the form cylinder.

The auxiliary impression roller K is borne at the lower end of an arm 0which is pivotally secured to the frame of the machine at P. The

angular relation of the arm 0 to the frame of,

the machine is regulated by the screw Q, which acts upon a short arm R,in a manner which will be Well understood.

The longitudinal adjustment of the roller K is controlled by the springS and the lock-nut T, in a manner which will be clear from the drawingand requires no detailed explanation. As explained above, while it ispreferable to so arrange the auxiliary roller K that it presses the webagainst the form cylinder, it may be desirable that the roller beslightly spaced away from the form cylinder, and the adjusting meansjust described permit such an adjustment to be made.

The operation of my invention will be clear from what has been alreadysaid with regard to its construction.

The advantages of the invention consist principally in the fact that thesame provides an efficient and easily installed and operated adjustablemeans of securing the contact of the paper with the form cylinder A overa greater space than has been practicable in printing machines as usedin the prior art. By thus hold-- ing the paper in contact with the formcylinder for a greater period of time, it has been found that a greateramount of ink is drawn from the form cylinder to the paper, thusproducing greater depth of printing. In rotary photogravure printingmachines as ordinarily arranged in which the paper makes only a line ofcontact with the form cylinder, a considerable amount of ink is usuallyleft in the etched portions of the cylinder after the contact with thepaper, but by carrying the web along in contact with the cylinder inaccordance with my invention, the paper will take up a considerablygreater amount, or practically all, of the ink from the etched portionsof the cylinder, which greatly increases the depth or contrast in theprinted picture.

I do not limit myself to the: particular details of construction setforth in the foregoing specification and illustrated in the accompanyingdrawing, as the same refer to and set forth only one embodiment of theinvention and it is obvious that the same may be modified, within thescope of the appended claims, without departing from the spirit andscope of the invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is as follows:

1. In a rotary photogravure printing machine, the following elements incombination: a supporting frame, a form cylinder, a main impressioncylinder, and an auxiliary impression roller resiliently mounted andadapted to hold a web of paper in contact with an arc of the peripheryof the form cylinder beyond the point of engagement of said formcylinder and said main impression cylinder, said auxiliary impressionroller being swingable angularly over the periphery of the formcylinder.

2. A'rotary photogravure printing machine as set forth in claim 1,characterized by the fact that the auxiliary impression roller isconnected to means adjustably and pivotally secured to the frame of themachine so that said impression roller may swing angularly over theperiphery of the form cylinder while maintaining said web of paperthereagainst.

3. A rotary photogravure printing machine as set forth in claim 1,characterized by the fact that the auxiliary impression roller isconnected to means adjustably mounted on said frame so that said rollermay be adjusted angularly over the periphery of and toward or away fromthe form cylinder.

4. A rotary photogravure printing machine of the character describedcomprising in combination a supporting frame, a form cylinder, a mainimpression cylinder, an auxiliary impression roller engageable with aweb for maintaining same in contact with an arc of the periphery of theform cylinder beyond the point of engagement of said form cylinder, saidauxiliary impression roller being yieldingly and adj ustably mounted inmeans secured to said supporting frame, said means being angularlymovable over the periphery of the form cylinder and manually adjustablerelatively to the supporting frame for varying the length of the saidare of the periphery.

5. In a rotary photogravure printing machine, the combination of asupporting frame, a form cylinder, a main impression cylinder, and anauxiliary impression roller adapted to hold a web in-contact with an arcof the periphery of the form cylinder beyond the point of its engagementwith the impression cylinder, said auxiliary impression roller beingreciprocatingly movable relatively to means securing same to said frameand angularly movable over the periphery of the form cylinder whilemaintaining contact of the said Web with the form cylinder.

6. A rotary photogravure printing machine of the character describedcomprising in combination, a supporting frame, a form cylinder, a mainimpression cylinder, an auxiliary impression roller engageable with aWeb for maintaining same in contact with an arc of the periphery of theform cylinder beyond the point of engagement of said form cylinder andsaid main impression cylinder, said auxiliary impression roller beingsecured to means mounted on said supporting frame, said means beingmanually adjustable relatively to the supporting frame for moving saidauxiliary roller angularly over and towards or away from the formcylinder, and thereby varying the effective length of the said are ofthe periphery, said auxiliary impression roller being resilientlypressed into contact with said web by spring mechanism, said springmechanism being secured within said means, and other means within saidmember for varying the tension of said spring mechanism whereby theauxiliary impression roller may force the web with a variable pressureagainst the form cylinder.

JOHN F. SPRINGSTEAD.

